The Stud is the Studly brother of the Colt but with some added stability. This means the Stud will handle the wind better and hold flight characteristics longer. The Stud is equally at home driving, approaching or putting in windy or calm conditions. XT is a durable, rigid plastic that has good tactile feel in the hands. Long lasting wear, even on rugged courses, means you'll get more rounds out of an XT disc.